JP3995335B2 - Airflow crusher grinding system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to the construction of an efficient pulverization system using an airflow pulverizer.
[0002]
[Prior art]
Conventionally, for a pulverizer, particularly a pulverizer with a built-in classifier, in order to enable stable and accurate pulverization classification, the amount of powder retained or stored in the classification chamber or pulverization chamber is adjusted, and the indoor powder It is known that the body concentration needs to be kept constant, and that the rotation speed of the classification rotor needs to be kept constant.
[0003]
However, in practice, as the pulverizer is operated, the amount of powder staying in the classification chamber or pulverization chamber increases and the powder concentration in the chamber tends to increase. As a result, there is a problem in that the coarse powder of the cocoon originally blown to the outside by the classifying rotor is sucked to the inside, and the coarse powder is mixed into the selected fine powder.
[0004]
Therefore, when the pulverizer is operated, the following items are detected and the operation is controlled based on the contents. First, as a powder concentration detection, an optical detector is used, or a pressure difference between indoors and outdoors is examined. In order to detect the number of rotations of the classifying rotor, a tachometer using optical means is used, or the load power is examined from the current value. Furthermore, the number of rotations of the classification rotor is kept constant by using a motor with an inverter or a synchronous motor.
[0005]
In addition, as the powder storage amount (retention amount) detection in the classification chamber or the pulverization chamber, the weight of the entire pulverizer or the storage portion is detected, or the accumulation amount is detected by a load cell. Furthermore, it is also carried out to remove stagnants and foreign matters and to adjust the supply amount of raw materials. In addition, as an auxiliary, the amount of air flowing through the pulverizer is also controlled.
[0006]
[Problems to be solved by the invention]
However, the above detection or control has been carried out as a measure that can be applied to each part of the pulverizer, and lacks the viewpoint of total operation of the pulverization system. There wasn't much thought about that.
[0007]
In view of such a problem, the present invention has an object to provide a convenient and efficient pulverization system, particularly when an airflow pulverizer with a built-in classifier is used.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, in the present invention, in the pulverization system of an airflow pulverizer using an airflow pulverizer that collides and pulverizes the raw materials with a jet airflow, first sensor for detecting and the classification means for coarse and secondary grain size classification, is provided on the body side surface of central gas-flow pulverizer, a powder density classification means by the classification has been coarse powder staying in the airflow crusher And a second sensor for detecting the amount of coarse powder deposited in the airflow pulverizer, the powder concentration detected by the first sensor being a predetermined level. When the concentration exceeds or when the amount of accumulation detected by the second sensor exceeds a predetermined amount of accumulation, the coarse powder is continuously or intermittently extracted, and the extracted coarse powder and raw material are extracted . the mixing means, predetermined Stirring at case, after mixing, and re-supply arrangement in jet-mill.
[0009]
Moreover, it is set as the structure which performs a compounding process by adding a predetermined | prescribed chemical | medical solution when mixing by the said mixing means . Alternatively, using a mechanical pulverizer as the mixing means, in the mechanical pulverizer, and pre-ground while performing the mixing of the said coarse powder withdrawn material, complexed by the addition of certain chemical same time It is set as the structure which processes.
[0010]
Further, the classifying means is arranged at a position offset sideward from the upper center of the airflow type pulverizer.
[0011]
In addition, a classifier that performs formal classification is connected to the airflow pulverizer, and the fine powder classified by the classification means is further classified and selected by the classifier only to fine powder within a specified particle size. .
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram illustrating a pulverization system of an airflow pulverizer according to the present invention. In the figure, reference numeral 10 denotes an airflow type pulverizer with a built-in classifier, which has a substantially cylindrical shape with the upper and lower portions narrowed. Here, the raw material supplied into the crushing chamber 2 through the raw material supply pipe 1 as indicated by an arrow A is directed from a plurality of (at least three) nozzles 3 attached to the lower part of the side surface of the machine body to one point in the machine. Accelerated by the jet of air jetted as shown by arrow B, and pulverized by collision between particles.
[0013]
Then, the crushed raw material rides on an ascending air current, fine powder within the specified particle size is conveyed as shown by arrow C, classified by the classification rotor 4 arranged at the upper part of the machine body, and discharged through the discharge pipe 5. The The discharged fine powder is conveyed to a classifier to be described later that performs formal classification as indicated by an arrow E. The coarse powder that has not been classified in the pulverizing chamber 2 descends as indicated by an arrow D and is pulverized again. By the way, stainless steel is mainly used as the material of the airflow crusher 10, but the inner wall of the crushing chamber 2 may be coated or lined with resin or ceramic to prevent wear or adhesion. is there.
[0014]
Here, as shown in the figure, the classifying rotor 4 is arranged at a position slightly offset from the center of the upper part of the machine body to the side. In order to prevent this, there is a possibility that the classifier 4 jumps into the classifying rotor 4 and cannot be accurately classified. In addition, 6 is a motor with an inverter, and can control the rotation speed while rotating the classification rotor 4. For detecting the rotation speed, a magnetic sensor type rotation detector, a rotation detector using a square wave pulse, or the like is used (not shown).
[0015]
Further, the powder concentration is detected by the sensor 7 provided in the middle part of the side surface of the machine body. In addition to electrostatic capacity type, vibration type, tuning fork type, ultrasonic type, microwave type, radiation type level meter, etc. that detect the storage state of powder, There are sensors that detect the internal state by looking at the movement of particles by shock waves generated when they collide with the aircraft wall.
[0016]
Further, by supplying a predetermined chemical solution into the apparatus from the chemical solution nozzle 8 provided therebelow, it is possible to perform a powder compounding process. There are various contents of the composite, and for example, powder particles are coated, colored, magnetized or charged. The chemical solution referred to here is not limited to a chemical solution, but also includes a slurry or fine powder of resin, pigment, inorganic substance, organic substance, or the like. The same applies to a chemical solution added in the mixing container 17 described later.
[0017]
As pulverization is continued by the airflow pulverizer 10, the coarse powder stays in the pulverization chamber 2 for a long time, the powder concentration in the pulverization chamber 2 increases, and the rotation load of the classification rotor 4 increases. There is a thing. Moreover, when it becomes a powder of a certain particle size, it will be deposited in the lower part of the crushing chamber 2. And it becomes impossible to supply a new raw material. Therefore, when this powder concentration is detected by the sensor 7 and exceeds a predetermined concentration, or when the amount of accumulated powder is detected by the load cell 9 provided at the lower part of the machine body, and exceeds a predetermined accumulation amount. etc, in order to discharge continuously or intermittently the accumulated coarse powder to the outside of the apparatus, a screw feeder 11 provided in the lower body is driven by a motor M _1. At this time, the rotary valve 12 for air sealing is in an open state.
[0018]
The coarse powder discharged from the rotary valve 12 is collected as indicated by an arrow F and is put into a collection hopper 13. The recovered coarse powder is supplied to the mixing container 17 as indicated by an arrow G by the screw feeder 14 driven by the motor M ₂ . The initial raw material is supplied from the raw material hopper 15 to the mixing container 17 as indicated by an arrow H by a screw feeder 16 driven by a motor M ₃ .
[0019]
The screw feeders 14 and 16 use an on-line flow meter as necessary to supply a fixed amount of powder by controlling the number of rotations, and to adjust the mixing ratio of the recovered coarse powder and raw material. It also works to adjust. As a result, the powder charged at a predetermined ratio is uniformly stirred by rotating the stirrer 18 in the mixing container 17 as indicated by an arrow J, and then the raw material is supplied as described above. As shown by the arrow A through the pipe 1, it is supplied into the grinding chamber 2. At this time, as shown by an arrow I, by adding a predetermined chemical solution to the mixing container 17, the powder can be combined.
[0020]
The bulk of the powder in the mixing container 17 is detected by a capacitive sensor 19 provided on the side surface of the mixing container 17, or the mixing is performed by a load cell 20 provided in the lower part of the mixing container 17. By detecting the amount of powder in the container 17 and restricting the movement of the screw feeders 14 and 16 based on the detected amount, powder exceeding a predetermined amount does not enter the mixing container 17. Reference numeral 21 denotes an intake port which functions to introduce air for preventing the material supply pipe 1 from being clogged with powder. However, the air to be introduced into the airflow crusher is not particularly concerned, depending on the powder to be handled and the content of the treatment, an inert gas such as nitrogen or argon, or a halogen gas for performing a chemical reaction simultaneously with the crushing. Etc. may be used.
[0021]
FIG. 2 is a schematic view showing a modification of the airflow type pulverizer. In the airflow type pulverizer 10a shown in the figure, a plurality of nozzles 3 attached to the side surface of the machine body are all directed obliquely downward, and the nozzle 3 is attached to the lower surface of the machine body vertically upward. The jet air currents ejected from the nozzles 3 collide at one point 0, and the velocity vectors of the air currents cancel each other.
[0022]
In this configuration, by attaching a screw feeder 11 equivalent to that used in the airflow crusher 10 shown in FIG. 1 in the vicinity of the nozzle 3 that is vertically attached to the lower surface of the airframe, the airflow crushing is performed. It can be used in the same way as the machine 10. Other configurations are substantially the same as those of the airflow crusher 10. However, the inlet side of the raw material supply pipe 1 is omitted here. The airflow pulverizer 10a is applied to heavy powder that has a large specific gravity and is difficult to be fluidized by the airflow pulverizer 10.
[0023]
FIG. 3 is a longitudinal sectional view schematically showing a classifier connected to the crushing system of the present invention and performing formal classification. As shown in the figure, fine powder and primary air (air) from the airflow crusher (10 or 10a) described in FIG. 1 or FIG. 2 are supplied into the machine through a raw material supply pipe 101, and the fine powder Is agitated and dispersed in the fluid chamber 102 to loosen agglomerates and to form single particles. Then, the fine powder rides in the ascending air current and flows into the classification chamber 103, and only the fine powder within the specified particle size is classified and sorted by the classification rotor 104, and this is discharged outside the apparatus through the discharge pipe 105. The discharged fine powder is collected by a collector (not shown) such as a cyclone or a bag filter disposed later to become a product.
[0024]
The fine powder from the pulverizer is supplied to the classifier by connecting the discharge pipe 5 of the airflow type pulverizers 10 and 10a and the raw material supply pipe 101 of the classifier and supplying them together with the air. After the fine powder discharged from the vessel is once collected by a cyclone or a bag filter, it may be separately supplied by a feeder such as a screw feeder.
[0025]
On the other hand, what is not classified and classified by the classifier descends along the wall surface as coarse powder, is stored in the lower part in the machine, and is discharged outside the machine through the rotary valve 106. Reference numeral 107 denotes a secondary air supply pipe, and 108 denotes a motor that rotates the classification rotor 104. The coarse powder discharged from the rotary valve 106 is collected, put into the collection hopper 13 shown in FIG. 1, and reprocessed as the collected coarse powder in the same manner as described above.
[0026]
FIG. 4 is a longitudinal sectional view schematically showing a mechanical pulverizer used in place of the mixing container 17 shown in FIG. In FIG. 4, the raw material and the recovered coarse powder are supplied to the hopper 307 instead of being supplied to the mixing container 17 in FIG. 1, and a predetermined chemical solution is also added here if necessary, and the raw material is supplied by the screw feeder 308. It is supplied into the machine via the pipe 301 and is pulverized between the blade rotor 302 rotating at high speed and the liner 303 around the blade rotor 302.
[0027]
The pulverized product is guided to the classification rotor 305 by the air flow supplied through the air supply pipe 304. The fine powder selected here is discharged to the outside through the discharge pipe 306, and the coarse powder is returned to the pulverization section. So that it can be reground. The fine powder discharged through the discharge pipe 306 is collected by a collector (not shown) such as a cyclone or bag filter disposed later, and the raw material is supplied to the airflow crusher 10 or 10a shown in FIG. It is supplied into the crushing chamber 2 through the pipe 1. As described above, efficient pulverization and classification can be performed by performing preliminary pulverization and then formal pulverization.
[0028]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a convenient and efficient pulverization system particularly when an airflow pulverizer with a built-in classifier is used.
[0029]
In particular, according to the first aspect, the pulverization performance in the airflow pulverizer can be stably maintained, and the quantitative supply can be performed while the ratio of the raw material and the recovered coarse powder is kept constant.
[0030]
Further, according to the second aspect, the chemical solution can be uniformly added to the powder with a simple configuration.
[0031]
According to claim 3, in addition to the effect of claim 2, more efficient pulverization and classification can be performed.
[0032]
According to the fourth aspect of the present invention, it is possible to prevent the coarse powder accelerated by the jet stream from jumping into the classifying means due to its momentum and being unable to perform accurate classification.
[0033]
Further, according to the fifth aspect, final classification selection and commercialization can be easily performed.
[Brief description of the drawings]
FIG. 1 is a schematic diagram illustrating a pulverization system of an airflow pulverizer according to the present invention.
FIG. 2 is a schematic view showing a modification of an airflow type pulverizer.
FIG. 3 is a longitudinal sectional view schematically showing a classifier that performs formal classification.
FIG. 4 is a longitudinal sectional view schematically showing a mechanical pulverizer.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Raw material supply pipe 2 Crushing chamber 3 Nozzle 4 Classification rotor 5 Discharge pipe 6 Motor with inverter 7, 19 Sensor 8 Chemical liquid nozzle 9, 20 Load cell 10, 10a Airflow type crusher 11, 14, 16 Screw feeder 12 Rotary valves 13, 15 Hopper 17 Mixing container 18 Stirrer 21 Inlet

Claims (5)

In the pulverization system of the airflow type pulverizer using the airflow type pulverizer that collides the raw materials with each other by the jet airflow,
Airflow pulverizer and classifying means for fine and coarse powder and the secondary grain size classification of material that is the milled,
A first sensor that is provided in the middle of the airframe side surface of the airflow-type pulverizer and detects the powder concentration of the coarse powder classified by the classification means and retained in the airflow-type pulverizer ;
A second sensor that is provided at a lower part of the airflow pulverizer and detects the amount of the coarse powder deposited in the airflow pulverizer;
When the powder concentration detected by the first sensor exceeds a predetermined concentration, or when the deposition amount detected by the second sensor exceeds a predetermined deposition amount, the coarse powder is continuously used. Or intermittently,
A pulverizing system for an airflow pulverizer, wherein the extracted coarse powder and the raw material are stirred and mixed at a predetermined ratio by a mixing means and then re-supplied to the airflow pulverizer. The pulverization system for an airflow pulverizer according to claim 1, wherein the compounding process is performed by adding a predetermined chemical when mixing by the mixing means . Using a mechanical pulverizer as the mixing means, in the mechanical pulverizer, and pre-ground while performing the mixing of the said coarse powder withdrawn material, the composite process by adding a predetermined chemical liquid simultaneously The pulverization system for an airflow pulverizer according to claim 1, wherein the pulverization system is performed.   2. The pulverizing system for an airflow pulverizer according to claim 1, wherein the classifying means is disposed at a position offset laterally from an upper center of the airflow pulverizer.   A classifier that performs formal classification is connected to the air-flow type pulverizer, and the fine powder classified by the classification means is further classified and classified into fine powder within a specified particle size by the classifier. The pulverization system of the airflow type pulverizer according to claim 1.

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